Guides for M. Rex Achievement

Omega Builds is the power you can use once your blue bar is filled enough. To see how much it's filled, check the blue bar in the top left corner.

Every time you score a good combo (up to 10 or more) your blue bar will fill almost fully. To use it, press RB and your character will start using an attack that's devastating to enemies. It will hit automatically, you just need to control the direction of it. It will most likely pop during your first playthrough. If you want this faster, then kill loads of enemies, and when they stop spawning, reload the checkpoint and re-do what you just did. After your 100th enemy killed, it'll pop instantly.